Various arrangements have been disclosed, and implemented in the last several decades, which facilitate imaging of a stream of discrete products in such a fashion that defective or unacceptable individual objects can be visually identified, and thereafter removed from the product stream so as to produce a resulting homogeneous end product stream that can then be further processed for some given end use. The various machine sorting applications that have allowed users to image, and then sort products have gained widespread usage in assorted industry segments. Further, much effort and research has been conducted in the sorting of food products in an effort to more accurately identify contamination, unripe food products, agricultural debris, foreign objects, and the like, which might have become admixed with the stream of products before final processing of the agricultural product has taken place. More accurate identification and sorting has allowed producers to engage in the sorting of bulk particulate products into differing quality categories such as when some products that may be identified as “prime” are sorted from products identified as “acceptable”, which are further sorted from products identified as “unacceptable”.
While great improvements have been made in various machine sorting applications through the years, shortcomings are still attendant with the use of the technology which is currently available. Chief among the shortcomings is that certain debris, foreign objects or unwanted material or unacceptable products/objects (collectively “unwanted material”), sometimes is not visually identifiable as the product stream moves through the sorting process. This may be due to any number of different conditions such as, but not limited to, for example, the unwanted material is in an improper orientation when imaged; the unwanted material has the same color as the desired product; the unwanted material has adhered to or is otherwise located in such close relationship or proximity to an acceptable product that it cannot be readily visibly discerned during the processing of the product stream; the unwanted material or debris is transparent, such as some glass and/or plastic, the unwanted material absorbs the electromagnetic radiation, the unwanted material reflects or refracts the electromagnetic radiation in a direction away from the detector, and/or the unwanted material is indistinguishable from a background such that the unwanted material is not perceptible by the sorting apparatus due to lack of contrast.
In any event, food processors, in particular, have strived to remove as much unwanted material, foreign objects, unacceptable product, and other debris from a product stream in order to ensure customer safety, and a homogenous end product for packaging and shipment. Food processors, for example, further want to ensure that the processing equipment does not produce excessive “false rejects.” These “false rejects” are acceptable product that has been mistakenly identified as unacceptable by the sorting system. This, of course, reduces the waste from the product stream, and also ensures that the food processor can receive the maximum available profit from the product stream being processed.
An object detection method and apparatus which avoids the detriments associated with the prior art apparatus and methods, which have been utilized heretofore, is the subject matter of the present patent application.